SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2da9c7d004a607c89de8f4c31add6e1683eebadc333413950466362d9563b11c' 
  AND token = 'L2Wms1uoJOufKNleWmUcAxar9wdb6RR1NtygMrtpA4Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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