SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf7dc0e1194fa9c9d9daf3285c81715024106f82a2980d02ae7de96967df2174' 
  AND token = '4fhQNMDLPL/FmozWkZFXfw6qTmgJTL8V6IHBAUAZTHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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