SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88cbd1a3a8711c0208a5a4f9b1b35002bd4350efed2aade8abf57cf2555e5c85' 
  AND token = '97Tf+edZCI45EaxkNmBuVRHGP4o3YoxkLdnPYZvjxDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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