SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b2320cac5453232ac86b5d7b209b6da7831c79c303973ec658994e5345d4132' 
  AND token = 'e1hWJkOp6Kn0HwPbS65gD+6WH0EAJ5edHqq/haT0/II=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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