SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '891a529ff88492044e96aca437f8321f2e8c22e496678d3d7db54f0207cc0ef7' 
  AND token = 'PPSb9MKPYX+3ymzRjsuY7qQSCz/G7XS8ibP5VejuZd8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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