SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87b32ee3e5f5c6564081d7ad6e8c13344c71f5855e6f54a3f067b86ee3201dc8' 
  AND token = 'YfJI+fZuwJzPZnMHDxghldkLPcpiK7pfOZhV7M/Ciyk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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