SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c01e981d966c0a0af4aa2d74e1c3d2b634382f7bad0285085aec82e3c924657' 
  AND token = '3YpAoDA0695SlwmTcxbZu+MRjAeGTsTeXgFIC39hHPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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