SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3e242440c0da1d5050dc801d622d8933fe7bd4047f8b0ed0f923ac980f2a1292' 
  AND token = 'UY6SgShWXojh7Q1ARnUBeJw0x5+w4kCf3f9MzNWArXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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