SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e82b79718dfe2c7aa76b8b4d7065d37acf5acd66e10dec52583eb29233ebbc94' 
  AND token = 'KZwNf6iGCP/DoFD0Lx2B+Tx/hKKZD9fS704RqOmQsp0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}