SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f84dde2c98565c00fd6a4359feef230f0e261b9af7699ac17a17fb9aa6aed05' 
  AND token = 'WoWtzZKyAKjdVxiVXtSmf20rVbHX8TLGWvhKjwlBLJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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