SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0712f59f8648b5b6437817637cd17061a7af3a5d6f742766b178274dfc15bd9' 
  AND token = 'A1ivJiiYnEXFIsv3AL1Tg9j+qgWb2dpTX2M39JkvAcI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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