SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e98be5fb52af1ec9500408ce4bfe756ec10cfb2fa6fad9638a74e1af33fff14a' 
  AND token = 'Yz9DFHQMrIhhcUmXeBZALjFEoa2D6rrIUwd2/qgIPEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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