SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d4cfaf5c533adb83357d821b3a5b1b5fa8a9a964a0ce80f17de9666925f6f58' 
  AND token = 'kQE/VGBYZmCys+5+yh+IywpVzXcXL906wIT9IvVj8AA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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