SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e59775991f53733d05191e79a6cd3ed34e368587502b104eb0435083d9a007dd' 
  AND token = 'SOberrJYzQ8wrz9FSmwYf4w8IswoBozvm3yWzSP6MY8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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