SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '795dd39f2b6031863636c32407f476421fc75ef2c14909d11850ed27e873d15d' 
  AND token = 'MF0X0VS/NWy6Dpu5MhASYaIVoXg6rGuzVrJYnvUHGwE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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