SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '605600fbe9b3a94396f6dd69541bf17d172ea7cb06a105e64a64321d753ebe9c' 
  AND token = 'YQzcGZDFH/v3ZA5RiA4Y3MsV/qN88fBH37iz11ipN0E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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