SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '510afc0ba814bb815dc3115e15fd8753a6eb9df5d372bf42068c7d785c75207f' 
  AND token = 'XiC1wd76vzCy4E6x17gktQYm/qQpVQtqm0KgLL9Xe/c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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