SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c0d687b69fda4fc8dde7f2873fcd581b5c870998504248fb45195f32e4040f3' 
  AND token = 'RnKp9bBMjDNGDywLZzAu57Hl4FdVaXQ7GBF8YUp7hbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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