SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '22a71d37441a529958f180ff2ea003cbb33c10c81f0a041d65241f99e5e89239' 
  AND token = 'u1e4wvyNfrvs8bQ1TSSGIJYXrLTdLFL1SCFgmnlwRVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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