SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23b3566704f9f9755c6f95dc4e4445bf70d75d248a9f1cf9935664420fa9e914' 
  AND token = 'dnaAEpPNYnws+NUGg1/GG9VB1dCu8BBzptN+1Ktg9Jw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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