SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8b9827a218de6356bf0a97b432ed8b53dfcf68f31af101f522413194093ab2b' 
  AND token = 'q6ASVsYbd7h0/oKruMSKBJ1TQQOP1ctJtRmqu6LDU3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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