SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '254b675fd1a33a7c4779a9b89a12fb83bbe70bc64dacc0b4d773a78deee904fc' 
  AND token = 's7QTnOJHT6ZeHmD3FXvgE2JUSBnxizR+0QbzOgBqby0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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