SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a4b877d6ee6c7b9c13cc1554a9845772feeeeb226612f5d5bb35a9899695dfc' 
  AND token = 'Vukxe1ByQV324S7hveZVNrXgx4hJgTPIqr8xzoqjraY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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