SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2eeb3255121a9d79f7728357cd77e1f6f7d424f42775b76543bd65f0263502bf' 
  AND token = '1gXJWFGk8adYOsts6HUf21sOqiDmbh/KzEbMp6ZvDJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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