SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1915f6d535a16465350670799e56a0f0b679fb549f92a8b67ec38a8dc7fdfbd4' 
  AND token = 'ShHXGQva1FoBD0IDRLUDs1vwbA/rLbg8/PqomD221Cs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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