SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd241fdbe3636acf8f87a389bd66521e6527c0ee2f90b358d63773663a3e2ee6e' 
  AND token = 'J+oBV1uzFjSGKEL0nlOjZB0txJi+KOOFBDfBhens/DI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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