SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4111d2353c103490e6004ece051d557e0a2661c8fd0f5ab4337436f80bf55fb5' 
  AND token = '/2/sFnpjA9m2m3RBwODthGJG/F8INZIYqQ9QVyGmn2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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