SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d328b2f65ac6d38115bc3372df0115a016f2f59946b2fc1de712bd4bb447ed2' 
  AND token = 'eUURxKYMR/ttzQiZDCiWsjzjys2NrBTExYbeciHaVpg=' 
  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"
    }
  }
}