Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9b6bbe78ba7d9f977a72fe4c56f0e5d47b6f493f15fe275a1e7ef3d0f931f18' 
  AND token = 'aP4jRKCGELM0YqdSBGs3m2S1AZiek+3BENdaeHjBDvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}