SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '599ee491b46ebf7d2f2cd1277da118833a3e2ab98008e8279f919fefb00b068a' 
  AND token = 'D0eh7qvQlBH8dQzWELD3vPTbJ7N06Ons2kL8JK4GXUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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