SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a7930f4d2439849f8eeb6ba9d4314d714780f7ece3b4fb42b9a76d78fad16d8' 
  AND token = 'ntZ+nBvxo7WYR5zvvGmZ/FKB/LWHyRl6ROGCdQaD83E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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