SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07b9234c32665d3d7d510a93000947be672ff4145a482f4189787bc682c3fef5' 
  AND token = '5zK5PZYSGGR4byduFij7YrOJCxM2zM0t9dxl1AvTTqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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