SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7cdb02c5b5c6d7c2c30868b91fc0a73386a6e175b27a80a2241d0db3a476299b' 
  AND token = 'pOPrCUFoffZ/HUOvBkTcbqcPYTg3ifBfoxmmNbZOJi8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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