SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7f71e7cc596199d86b2d2c397dcb8b274fc56f29d98bce578c197639c147cce' 
  AND token = 'MJd8FF1M0hmshbsOr4KgD/+zSg4il2f4JVS6hDz5qhA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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