SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e95fcaa140e4b53f7af733574b4bfaa6ce296b3619d139102d8e32e2cc836bd' 
  AND token = 'sQVBZmTFDVYXUaYEzMqACrEd6IFgnXooRNl+auFzc3g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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