SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eeb91b644c8c76f06db77f199f2e7ae1f2b7e142a344127052772085876d3215' 
  AND token = 'BBZp75CklN5wQfrfo2IgZ9sG/wK3Ls+QlbvHhaVBw8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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