SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8aad31399cbeab13c7cec426c799695086e71ff081edfb6a906a85e64a07d259' 
  AND token = 'TgqR+Z8JRXW68kVduEnqhBxPrIocJ2KqUAopQQb05nQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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