SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52c1517834487321d6be7e04f705f8ae01ba1579fc52ff02c7a93a406be7255e' 
  AND token = '1pO/oHRnjksZHGiqzC+Yb9KCK4pXY3/x9ZwfDwHbUYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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