SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '25ac233124911f439044b53c20103bff3834af2e96a4940240a6fbc8dd9ec905' 
  AND token = 'Qx8iCMpwVBOvI+diMYCZYkxRyajgGjgnyjGzNyAh8Ag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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