SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b9448195e0cfec1471441835a8b2af2cf6ac4664db0e328ad1f4461f55a53305' 
  AND token = 'blyd2gcZNmZI7elrRqeioL5uMoh+B7HWjp2MFJ+EVqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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