SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5a45c75d69bd9faf1cebf62a39d085330c11e94385110d8668f914b4a02ac77' 
  AND token = '5vfuQvnHVMAGh9qq/4kJKYG2G76rccTDU2WolX0nA9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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