SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '102cde016296b522f75503cdfbd410720300ff4f52561ee6f755173d97778dbb' 
  AND token = 'Alzj/xF2vcrRshhA14+z9j4aC+YuBaG2ska2+rJBTxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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