SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16344c546b185ec05ff8857c2be7ec6d376091b3e14e6d31d5d508406114888c' 
  AND token = 'rqGWkhIxTp3DRxL+ddfjk7k77eF5c27yzomxzuGfofk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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