SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a37e25b9bb34e4440a99e636f0165b976c280d08f135b13193eb717c49d83a86' 
  AND token = 'v7NKEVLWJ8TvjapAKhHzXREx8fHlKZLhJvgyDWG6tC0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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