SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ca4b6806bb67891c1d9458e5dc6c7a3842d9453d7a903a41621f825a4f8de76' 
  AND token = 'KIGKcnrQm1qjTHdE9y6WphMVQ1nQCncLOJ1CLFkjTt4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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