SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1b19ec154d2fa16db7433aad3cd85195319bdd174390241d522d44ffe7efb9e' 
  AND token = 'elpBmsidEW/9b1QF80JgBFNWmLQ5PIkkDG70FYw/txk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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