SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fbab0bc36cb998b4d422da26a84d7944b3fa691b1984121f1af45914e88d4545' 
  AND token = '1jGS1+ROsJ2MLE4xk2h9WhidWgBDZQEdQjfAnvd/xJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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