SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1784f2ef6fe604d3bbf035cdd2eb8100bca10c3fbcb5f38d08b43a044ef68bf8' 
  AND token = 'NXP56QnOKUOopLCNn3Uk6NPyKvZaLZW1tNfwaur0E3E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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