SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'da307cd0c3bcdaa73edf9a6aa26715cce40c9fc16e256afc2426fef22a11a6a2' 
  AND token = 'DyIVj9pnsNdlVTXsbrkuC75MPCjgszS1MQQa/cKc5h0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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