SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd175732d978a998bd305ad1f565c5875075a7a805a857ecf32e4065c7ef1673d' 
  AND token = 'OzztbniungJLwZVOTSIiyHhDB5xBOhb44N8QNr9HqV0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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