SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '691497929bffab349e1027afd869963cdf07473ed414022323584d9a71688f43' 
  AND token = 'vPvlJ9uw6UISxN46maUU2k0HY/J7KPo1nQ+TnH900eI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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