SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'faf1546b25de90b8cdc870ff4fa0e90bf681cdd8c58bdffd644baba0bb4c7dc1' 
  AND token = 'gzNoqzioDOkB+S99KA4iczjUQq41D1CCgOqrMtqmbU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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