SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aeaf66b2a1c5eff87aa5556fec358d6fd9ffe8df4851ec6d29851ffd36ba6083' 
  AND token = 'uAZaOO9DcyZKrafxe96S4sTDMN0S3kRrxNz1vsesY4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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