SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9918074be4dae5448290279d33cdcc413d900dec1ca25171f082198a3d97988' 
  AND token = 'ZVeZ9OMRV8szk4YdSwSa1vy5rSqK5wdgR+EQ7tFESVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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