SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ba80a5ec26b93da587b1fb1379191532af9bf29b3e8ddcb95c16f7eb4125022' 
  AND token = 'mDnLeXceURYlWLzsUmeAG8mHBzolmy4Dg8ix9Ap8+jA=' 
  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"
    }
  }
}