SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0f8a53d7e480aed552645edeba947fe84aaef924b42a5a956fa2b96c3eb4020' 
  AND token = 'ThVl3wHe2LDBQ/H7yK19pK/6HmKjYB26dEUGBnNVYNI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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