SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a9dd9360c08e11f851b1ceb289921397684389ee6998c5de649a3563a41544b' 
  AND token = 'ykkneCOxfsGovu3bTzVBmfhaRnnci1mGegzVfVKLtdk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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