SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bd65edecf2794fb7d34890837247687f85fc476623a5d27289559034ff7b2e75' 
  AND token = 'C2yTZYQEUFyek+w8fRXjgmqEeb0znr3LI9GAMwFldW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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