SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4552da8b404ec7a7b5766968406210986634f0e02d55d6ca7bd73722051297e5' 
  AND token = 'Swth/FcPnShW8fk/BFEl6XTLnYU6UdB5D0Y1Igu+Scw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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