SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc44afc0fec3064486fe91588277776468e47b3fc99131e28d0b0fb3499803e8' 
  AND token = 'UntgbVpBEcToxaJWwFzN4Oyw52jXrwAcCj9lh8KRILc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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