SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34ae16915e78f7bd2c682debf6b12a3aff797200a136d82e5ab0d27ecd6ce3ec' 
  AND token = 'rmEZTxVUp42QFQOcnFmqzQLX4b2PDYYocNn1vTtybqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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