SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c7ba33417a4a3952ddac25e4c8e6cbc5b2a1367c840be0e62bd3f3c6f067e9d' 
  AND token = 'cKQ4ugmgIvGc7Fyj5hirkjhwNJzB/WAGUGku2X+jUE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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