SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfac2196b18b83ebcfb84406dd07c2a88b7b4648a0f372327e5d6fc09fe030df' 
  AND token = 'nKffKDoAnVsCl7aeCrWk22Dt94b+I2/+IhZ05erVM7M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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