SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9eef61fcedf6564d62930bbc3922081422986c929da502cc6899d9841e34adc6' 
  AND token = 'hDyNVHLqIMp7M1jE2vhM3IEa/vh+29BeuCMwanIT6Z4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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