SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84623de373235a68e9c45a956a8dd6b0b515e5199fd24987dcef25409640a02e' 
  AND token = 'KBOfCChUjbx6rkIivwvV5GJe2HZoypm3j1evjvZOcls=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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