SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1134c5c69a9ef08bb8bf67998a3d02d61e277bdc0b8a47ca68e7612274af1887' 
  AND token = 'b16uqtIZ1QYrZUvfwfKN1eQgmoSAK6JBXs3xT+DeYyE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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