SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e78bf91563d7cd8ae8b12e13af804ea1cbc7175388bf9db9f8bbca7283759092' 
  AND token = 'QA68n/yRVsmxUGLSqIRooDViqqiHuBNwwf0eI4WZ9HM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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