SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fc7e9e68f3be19001d14a331ff0b18779b571d924d213abc822f6553702c2f6' 
  AND token = 'evZkCKXFxDjmw1CiLrGxAU85hfnHQsO/uaOjZIZDE3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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