SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c36052d6a3f373b9b37fdd6c28df31bba68aca219e6ecbc19d6fbedc40edaaf' 
  AND token = '8c4NShvRsS8WBA86kox9i3PKh8nSrzaKcK9rpYcblPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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