SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd299728940b48d0155912d37ed8a1e3056f44886a9755a8ce042bd9db0684cd2' 
  AND token = 'H7lWC627TBIH3JjZWXj0rFL1Cm+zhmD6VYPufBKx1ic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}