SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '552dd24428090a9f7c2855b161546ff46955dfbe142db8ab5643f2fa7a97bfcb' 
  AND token = 'p4POvjGlx2yiAoBhg4DVcgjWz+/YTtj7LXIRTlt4l/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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