SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b54496b3e61f9ed670f3f33cc7520a9c1238cbc01d69a275a56dfa21edfbdf87' 
  AND token = 'C5wALg+uAGPnLQ74Q8ZlV9870DKxXt0K/lLZj4YKi1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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