SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '884727eec5fd2fb63a452ccc5d62748400738fa7695b02d80d36c3f95723859a' 
  AND token = 'xGqpjIewgA0SYn6JYr7rkSRD++1/3E9GhVW7dUCQHtU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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