SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c5d7d9371c57dddc6d8926719ebc55c37e605f9629a5332356feb339e610e73' 
  AND token = '/VEbODVJCNlYJGAwdQNYTUKOzMOBNTQBubMoQ2DcPnQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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