SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '472fa2007ba9340e22f0fbc88a5b3df33d92f92c1f64691c73d8631669a11d6a' 
  AND token = 'eu15w+SHjBgb+eSWcqurjyQ03TzZiV+8qkcAvtxD/14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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