SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '817fd4abe445dcac16cfce8e6f24e5ba93d29bf11a8b3881fa1c70c4ada5b4dd' 
  AND token = 'iRPre28C9vXlVIuGKZq1SJ4vJzBp3bFrZKM/93gqllw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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