SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c7328e568f51ddc02debd35fa58fa191acc87ca1769e48716afc7e107c75a82' 
  AND token = 'H83xiQIB2rNCEHiZVaXfvvEGNf5SemhHQBfKkVATpYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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