SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '17498af29f820fa05415a779a90c4fb547e9e07f2c169a247f2fe03e503b7302' 
  AND token = 'vzC/rQO0MQ2zk+d+xym83XadDqFahwIrKpNrTK/GXqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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