SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71ffbfac91bb4d9f8ed467d18a0a49270892408930927730c45feeb39663bc06' 
  AND token = 'cSjxpjMnqWgoATXEpqU8wPKrKTHx8RXBu8wN4Dbb/tQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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