SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b3f2ee3ced5a2e74e521d071fc6bdc4e7dcdb83123b873ce7133ef451da19550' 
  AND token = 'm++hi4Vbn4hzTeJDjkO4sAa2o9ysTNsPGORioasNlOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}