SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1f5d1528f1eba8547ac251ca6b313eef16e03743583256d65272a6cf5998eb5' 
  AND token = 'jNyI0DiHqyv8m++kBVG6fmSbfNNOKgylnV05QyN1L3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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