SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb9e35a64450c6c32c8a1226c82933bba4eb3fda0b637a62b68669cb0a07267c' 
  AND token = 'mDVE0txzyjihEWB+bp/Q5NmLaGhY7YepyYSbIrUiSvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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