SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be18723a2fb129ab06c3de9977c38b4218f17f8f3d02782665c4db0dab9d2734' 
  AND token = 'IOD2VXtrJkWHC5AgEEfA4XD9xzhYaAkv17VBr2+ZE9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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