SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b2755da3377127a31a83c4936905e2044d6e108eba536544682711a6e7007248' 
  AND token = 'KWXA+U7RwpQHxLYRmh6usBxWxX5maYcJklpjC0DfMTM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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