SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56c1c781939d58fea882ca0947a3a82c46a55ab47fc43c059015144b590105ba' 
  AND token = 'rtn5tUSC8hoPERvh9oQfw0WA0Rb+9CMkgEia1l1Fji8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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