SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7274b2721744d9f891e03e4a57027bf0f4cd378116e0b02300bd221511a2a8a' 
  AND token = 'Ye8sZxHhvuUH/cI8TgKYxPoZ6uKFm+yBBrRQ5BlDgDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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