SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71434ab6a6af13605fb127a13d283544c28c38433cbc7fef87dead244178b057' 
  AND token = 'SBLiw+IBW4A36s+8ptxImV4slZxGj4k/NTjbeaM1YoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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