SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5df61a5d7ed38381b0be7299b5ff139442fd0b7fb8a19c2f03faa4c1f427e7e0' 
  AND token = '/x+ebcSi1kGIPqnq/wAIl7kYVzXBpyU0SvnueFTz9+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}