SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef205bb2afb11cd69bfbede01f8efb08f29889bde34957f207bcaa5cf14fab70' 
  AND token = '3xvNYwMXe8WQE6S1GOa2dY9TO4xoFerVrkR2ZC3gYJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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