SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'aca5df57eebad9528c5beb70e7ad0323820ec5dd432dd58111938982557fee28' 
  AND token = 'qkGghEzBniBWW7aVhKXL0X4qFfKVSR4LjSWQTLm1Udw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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