SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bc3a06ccaf0f3d21d9caf80691051aecfe8bc369999b65bec106e8f3c4744a0' 
  AND token = 'xGH2rBVr+fyXFqc9jijzQbsDq+7Jo/rBIHYVes7JjhM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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