SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc70fb093b2da981f4daa0925208ef87606f56390fed11c65a246f03a3a17857' 
  AND token = 'v9jJ3NCbXvjU1aJ7pJ9oSJVttK6ATOdl5yov98RK3Ao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}