SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fb224502b19978f48be17a62610c6943fe38f9eb7a21569553f6ae8627cde5e' 
  AND token = '5aJ/Hf8WVXHy78Qq3af/nOP5XyzICtaaKZtSdNMb544=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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