SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6eea7dbb38164fea1b260191f2b0671d340cbd1a30d087b43c77a8430d47b43f' 
  AND token = 'b2aXdQNotCF8APJY33dNdbKrnkHUfwmYx5DVDqwI7MA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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