SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dfdef5045bf7a37857f11e6819e53a3d8fc40c6ac60e6b2e8d0314ce4642146' 
  AND token = 'Kohb0cwqCt/6KYIg0iwgaqbZSMUyZ1LKlWaadlLl46k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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