SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9eba9abc7b56891768f9fcc595ffa3153a931428eeaf620bb8d3f67a9c7333de' 
  AND token = 'jvfzbwlrrHuz18mUTuO4kMWrPY0edKQjDeBFWWpscJ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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