SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccaa43708a2aa531d8b14b749efd1d58bf9cce72c83d17567ba407106200e447' 
  AND token = 'IlrLXnPfBGPCJEkipe1JXi38wyR12LB9WH24vshUoow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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